Reenforced-concrete pipe



Y Mar. 6, 1923. 1,447,112 L P. KIRCHER.

REENFORCED CONCRETE PIPE.

' FILED JuLY14. 1921. s sHEETshsHEET 1.

g y i I-I-l-l-I-I-l.

Mar, 6, 1923.

P. KIRCHER. REENEORCED CONCRETE PIPE.

3 SHEETS-SHEET 2.

FILED JULY I4. 1921.

Mar'. 6, 1923.

' 1,447,421.' P. KIRCHEH.

REENFORCED CONCRETE PIPE. FILED JULY I4. 1921.

3 SHEETS-SHEET 3.

PAUL KIRCHER, OF CHICAGO, ILLINOIS, ASSIGNOR TO MASSEY CONCRETE PRODUCTSCORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION' OF VIRGINIA.

REENFORCED-CONCRETE PIPTE.

Application filed July 14, 1921. Serial No. 484,556.

T o all w hom it 4may concern Be it known that I, PAUL KIRCHER, acitizen of the United States, and resident of Chicago, in the county ofCook and State of Illinois, have invented a certain new and usefulImprovement in Reenforced-Concrete Pipe, of which the following is afull, clear, concise, and exact description, reference being had to theaccompanying drawings,

forming a part ofthis specification.

My invention relates to a reenforced concrete pipe, and particularly toconcrete pipe suitable for use in railway culverts and for otherpurposes which require that the pipe be capable of resisting heavyforces Atransmitted thereto in lines substantially at right angles tothe longitudinal axis of the pipe.

It is the object of my invention to provide a pipe which comprises aminimum of concrete and reenforcing material in its construction, butwhich is nevertheless capable of resisting such severe strains' as maybe imposed thereon in use.

Heretofore, the most successful styles of railway culvert pipe have beenconstructed in accordance with the teachings of United States Patent No.7 09,7 94, granted to Walter C. Parmley, on September 23, 1902. My

present invention enables me to retain all of the advantages of theP-armley construe tion, and in addition aii'ords other importantadvantages never to my knowledge heretofore attained in a concrete pipeof the type to which my invention relates.

A detail description of my invention will best be understood when readin,connection with the accompanying drawings in which- Figure 1 is atransverse vertical section of a reenforced concrete pipe embodying myinvention; i

Figure 2 is a horizontal, longitudinal section taken on line 2 2 ofFigure 1, certain portions of the concrete being brokenaway more clearlyto reveal the nature of its reenforcement Figure 3 is a view similar toFigure 1', but illustrating a slightly modified embodiment of mylnvention;

Figure 4. is a view similar to Figure 1, but illustrating a modificationof my invention wherein wire netting is used as the reenforcingmaterial;

Figure 5 is a horizontal longitudinal section taken on the line 5--5 ofFigure 4;

Figure 6 is a view similar to Figure 4, but illustrating a furthermodification of my invention, and

Figure 7 is a view similar to Figure 3, but illustrating a furthermodification of my invention.

Similar characters of reference refer to corresponding parts throughoutthe several views.

Referring first to Figures 1 and 2, at 10 I have illustrated a concretepipe of circular transverse cross section. Imbedded in the pipe is areenforcing cage which consists of aplurality of longitudinal bars11-11, and a plurality of spaced pairs of transversely disposed bars 1212. The bars 12-12 are substantially U-shaped, and it will be noted thatthe said bars 12-12 of each pair lie in immediate proximity one to theother, and are reversely disposed. The bars 12-12 of each pair'arepreferably tied together by twisted wires or other attachment' meansindicated at 13-13. In practice, the longitu-V dinal and transverse barswill also be Wired or be otherwise secured together at their crossingpoints. The tying together of the transverse bars and the longitudinalbars is resorted to merely in order, to form a reenforcement cage whichmay be inserted in the pipe mold as a unit. Alter the cage has beenimbedded in the concrete the tie Wires have served their purpose.

It will be noted that the cage comprising the bars 11-11 and 12-12 issubstantially elliptical in transverse cross-section, the major axis ofthe elliptical cage co-inciding With the horizontal plane passingdiametri cally through the pipe. and the minor axis of the ellipticalcage coinciding with the verillustrated is intended to withstanddownwardly directed forces exerted thereon. When such forces areexerted-on the pipe, regions of tension exist at and near the bottom.Under the same conditions, regions of tension exist at and near theouter surface: of the pipe at the sides thereof, and regions ofcompression exist at and near the inner surface of the pipe at the sidesthereof I now call particular attention to the location and function ofthe end portions 12 of each pair of U-shaped bars 12-12. The bar ends12a lie outside of and project away from the boundary of the ellipsescircumscribed by the U-shaped bars of which they form parts. The pointsat which the U- shaped bars 12-12 of each pair cross, both at top andbottom, are located in regions of tension in intrados, but the bar ends12a project outwardly and away from such points and preferably extendinto regions of compression in extrados. It is desirable, of course,that the pipe wall be made as thin as possible. Furthermore, infollowing the teachings of the Parmley patent, it is necessary that thebars 12-12 lie extremely close to the inner surface of the pipe at topand bottom. Downwardly directed pressure exerted upon the pipe tends toflatten the ellipses circumscribed by the several pairs of U-shaped bars12-12. Thus, there is a decided tendency for the bars 12-12 to pull outof the concrete at the regions of tension in intra-dos. However, theseveral ends 12-12a of the U-shaped bars are disposed so that in eachcas'e there is a very considerable thickness of concrete between the barend and the inner surface of the pipe. The anchoring of the bar ends inportions of the concrete removed from the regions of internal tensionminimizes the possibility of the bars being pulled out of the concreteat the regions of internal tension when the pipe is forced to sustain aheavy load.

The arrangement illustrated in Figure 3 differs from the arrangementshown in the preceding figures in that the bar extremities 12a- 12a ofthe several pairs of transversely disposed 'U-shaped bars 12-127areprovided with offset portions or hooks 12b-12b. The hooks 12"--12bformed upon the ends of each U-shaped bar 12 terminate alongside of andare tied or secured to itsassociated bar 12 at points remote from theends ofthe latter.` The wires whereby` the hook endsof each bar are tiedto its associated bar are indicated at 13a-13a. It will thusbe seen thatin the arrangement of Figure 3, the bars 12-12 of each pair aretieddirectly together at six points instead of only at two points.y

' as is the case 'in the arrangement shown in Figures land 2. Thearrangementaof Figure 3 enables me to construct a much more rigid cagethan is possible when the arrangement sh'own in Figures 1 and 2 isemployed.

Furthermore, the hook portions 12b-12b to a very considerable extentresist the sheering strains which, when the pipe is under load, exist inthe concrete in the regions where the hooks 12"--12b are disposed.

It is sometimes desirable particularly in constructing small diameterpipe to employ wire screen as the means for reinforcing concrete againsttensile strains. In Figures 4 and 5, I have illustrated an embodiment ofmy invention wherein wire screenois used as the reinforcing material. Inthese figures, reference character 10 indicates a concrete pipe ofAcircular transverse crow-section, and numeral 15 indicates a wire screencage of elliptical cross-section. Cage 15 ex tends continuously throughregions of ten sion, both in intradosand in extratlos in accordance withthe teachings of the Parmley patent, hereinbefore mentioned. In order toprevent the possibility of the cage 15 being torn out of the concrete atthe internal regions of tension, I provide a pair of wire nettin sivewith the cage 15, and are tangentially disposed relative thereto. Strips16-16 contact with cage 15 along lines immediately above and below thelongitudinal axis of the pipe, and are preferably, tied (wired) oi'otherwise secured to the cage by attachment means indicated at 17--17.The lateral edges of the strips 16-16 extend from the internal regionsof tension into regions of compression and serve the same functions asdo the bar ends 12a-12a. of the arrangement s-howngin Figures 1 and 2.

In Figure 6 I have illustrated a modifi cation of) the arrangement shownin Figures 4 and 5. In Figure 6, the lateral edges of the strip 16-16are offset or turned toward the cage 15 and are tied or otherwisesecured thereto by attachment devices indicated at 18. The offsetlateral edges 18a-18a of the strips 16-16 correspond in location andfunction with the bar end hooks 12"-12b of thearrangernent illustratedin Figure 3.

In the arrangement of Figure?, the bar' extremities 12b of each bar12are disposed in lines tangential to the ellipse circumscriblng portionof its associated bar. In some classes of work, this arrangement isprefer'- able to that shown in Figure 3, wherein the portions 12b ofeach bar are hooked in toward the ellipse -circumscribing portion of theadjacent bar.

Having thus described my invention, what I claim asnew and desire tosecure by Letters-Patent of the United Statesis:

1. A reenforced pipe comprising a pipe body of initially plasticmaterial, and a re- `enforcing cage embedded in t-he pipe body strips16-16, which are co-extenpoints, and tension members associated withthose portions of the cage whlch lie adjacent to the inner surface ofsaid pipe and extending outwardly1 therefrom toward the outer surface ofsaid pipe.

2. An article of manufacture comprising a pipe body of initially plasticmaterial, and a reenforcing cage embedded in the pipe body and lyingadjacent to the outer surface of the pipe at substantially diametricallyopposite points and adjacent to the inner surface of the pipe at pointsintermediate said opposite points, and tension members associated withthose portions of the cage which lie adjacent to the inner surface ofthe pipe and extending outwardly from the cage to points adjacent to theouter surface of the pipe body. j

3. An article of manufacture co-mp-rising a pipe body of lini'tiallyplastic material, and a reenforcing cage embedded therein, saidreenforcing cage lying adjacent to the outer surface of the pipe atsubstantially diametrically opposite points and adjacent to the innersurface of the pipe atpo-ints substantially midway between said oppositepoints,

and tension members associated with those portions of the cage which lieadjacent to so the inner surface of said pipe, said tension membersbeing disposed substantially tangential to the cage and extendingoutwardly therefrom toward the outer surface of the pipe body.

4.7? As an article of manufacture, Va pipe body of initially plasticmaterial reenforced by a plurality of pairs of tension members embeddedtherein, the tension members of each pair being substantially U-shapedand disposed side by side in reverse arrangement, and in immediateproximity one to the other, each of the U-shaped members of each pairhaving'its middle portion positioned adja* cent to the outer surface ofsaid pipe and portions adjacent to the lends thereof positioned adjacentto the inner surface of said piper the ends of each of said l1-shapedmembers extending outside of the other members of the pair.

5. As an article of manufacture, an initially plasticpipe bodyreenforced by a plurality of U-shaped tension members embed'- (ledtherein, some of said U-shaped tension members being disposed reverselyto other tension members, and each of 'said U-shaped members having aportion thereof adjacent to theouter surface 0f said pipe and twovportionsadjacent tothe inner surface of said pipe, the ends of saidU-shaped tension members extending beyond the portions adjacent theinner surface of the pipe outl wardly toward the outer surface of thepipe in lines substantially tangential to the inner cylindrical surface0f the pipe body.I

l'6. AS an article of manufacture, an ini- ZEE tially plastic pipe bodyreenforced by a plurality of U-shaped tension members embedded therein,said tension members being disposed side by side in transverse verticalplanes, each tension member being reversely arranged with respect to itscontiguous tension members, each of said tension members having aportion adjacent to the outer surface of said pipe, and two portionsadjacent to the innersurface of Said pipe, the ends of said U-shapedtension members extending outwardly from the portions adjacent to theinner surface of said pipe toward the outer surface of the pipe body.

7 A reenforced concrete pipe comprising a circular pipe body ofinitially plastic material having embedded therein a plurality' of pairsof U-shaped metal bars disposed in planes at right angles to thelongitudinal axis of the pipe, the bars of each pair circumscribing anelipse, each bar having a portion thereof adjacent to the outer surfaceof the pipe and two portions adjacent to the inner surfaceof the pipe.

8. A reenforced concrete pipe comprising a circular pipe body ofinitially plastic material having embedded therein a plurality other,and having their ends crossing at substantially diametrically oppositepoints lo` cated near the inner surface of the pipe body, the middleportion of each of said bars lying adjacent to the outer surface of thepipe body.

9. A reenforced concrete pipe comprising a substantially circular pipebody of initially plastic material having embedded therein a pluralityof pairs of U-shaped metaljbars disposed in planes transverse to thelongitudinal axis of the pipe, the bars 0f each pair being reverselyarranged and disposed immediately adjacent one to the other, and havingtheir ends crossing at points adjacent to the inner surface of the pipebody, each U-shaped bar passing through' a region of tension adjacent tothe outer surface of said pipe, and through two reglons of tensionadjacent to the inner surface of said pipe, the ends of each U- shapedbar being provided with offset ends which terminate at points adjacentto the other bar of the pair.

10. A reenforced concrete pipe comprising a circular pipe body ofinitially plastic ma `terial having embedded therein a substantiallyelliptical reenforced cage, said cage iaving portions adjacent to theouter surface of the pipe at substantially diametrically oppositeJoints, and adjacent to the inner surface oi the pipe at points sufbstantially midway between said opposite points,

and tension members associated with said cage and extending outward fromthose portions of the cage which lie adjacent to the inner surface ofthe pipe, said tension me1nbers lying in planes substantially tangentialto the cage.

11. A reenforced concrete pipe comprising a substantially circular pipebody of initially plastic material having embedded therein an ellipticalreenforcing cage, said cage passing adjacent to the outer surface ofsaid pipe at substantially diametrically opposite points and adjacent tothe inner surface of said pipe at points substantially midway betweensaid opposite points, and

tension members associated with said cage and extending outwardly fromthose portions of the cage which lie adjacent to the in-v ner surface'of said pipe, said tension members lying in lines substantiallytangential to the cage, the outwardly extending portions of said tensionmembers terminating near the outer surface of the cage.

In witness whereof, I hereunto subscribe my name this 29th day of June,1921.

PAUL KIRCHER.

Witnesses: l

ALBIN C. AHLBERG, EMILE J. BOURGEOIS.

